Stamping die replica and method of manufacture thereof

Abstract

A method of making replicas of a master stamping die having a master die pattern in relief comprises first making a negative mold of the master stamping die. The mold has a negative mold cavity pattern corresponding to said master die pattern. One or more layers of die forming material is electrodeposited on the negative mold to create a replical die electroform having a cavity pattern like the mold cavity pattern. A thin electrically insulative shield is formed which has a opening pattern having generally the outline of the electroform cavity pattern. The shield is laminated on the replica die electroform with the opening pattern aligned with the electroform cavity pattern. A die material is electrodeposited into the electroform cavity pattern through the opening pattern in the shield to fill the electroform cavity pattern.

What is claimed is: 
     
       1. A method of making replicas of a master stamping die having a master die pattern in relief, comprising: making a negative mold of said master stamping die having a negative mold cavity pattern corresponding to said master die pattern;   electrodepositing one or more layers of die forming material on said negative mold to create a replica die electroform having a cavity pattern like said mold cavity pattern;   making a thin electrically insulative shield having an opening pattern having generally the outline of said electroform cavity pattern;   laminating said shield on said replica die electroform, with said opening pattern aligned with said electroform cavity pattern; and   electrodepositing a die material into said electroform cavity pattern through said opening pattern in said shield to fill said electroform cavity pattern.   
     
     
       2. The method defined by claim 1 wherein said shield comprises a thin sheet of plastic material and an adhesive film. 
     
     
       3. The method defined by claim 2 wherein said shield is composed of acetate. 
     
     
       4. The method defined by claim 3 wherein said acetate shield and film has a thickness of approximately 9 mils. 
     
     
       5. The method defined by claim 1 wherein prior to laminating said shield, a preparatory layer of copper is electrodeposited on said replica die electroform to promote adherence of said shield to said electroform. 
     
     
       6. The method defined by claim 5 wherein said replica die electroform includes a first layer of nickel followed by said preparatory layer of copper. 
     
     
       7. A method of making replicas of a master stamping die having a master die pattern in relief, comprising: making a negative mold of said master stamping die having a negative mold cavity pattern corresponding to said master die pattern;   electrodepositing a layer of die-forming material on said negative mold to create a replica die electroform having a cavity pattern like said mold cavity pattern;   electrodepositing on said electroform a very thin preparatory shield adherence layer;   making a thin electrically insulative shield having an opening pattern having generally the outline of said electroform cavity pattern;   laminating said shield on said replica die electroform with said opening pattern aligned with said electroform cavity pattern; and   electrodepositing a die material into said cavity pattern through s id opening pattern in said shield to fill said electroform cavity pattern.   
     
     
       8. The method defined by claim 7 wherein said shield is composed of acetate and an adhesive film and said preparatory layer is composed of a thin layer of copper which promotes adherence of said shield to said electroform. 
     
     
       9. The method defined by claim 8 wherein said acetate shield and film has a thickness of about 0.009" and said preparatory layer of copper is about 0.003-0.007" thick. 
     
     
       10. A method of making replicas of a master stamping die having a master die pattern in relief, comprising; making a negative mold of said master stamping die having a negative mold cavity pattern corresponding to said master die pattern;   electrodepositing one or more layers of die forming material on said negative mold to create a replica die electroform having a cavity pattern like said mold cavity pattern;   using said master stamping die as a cutting die, cutting from a thin sheet of electrically insulative material a shield having an opening pattern having generally the outline of said electroform cavity pattern;   laminating said shield on said replica die electroform, with said opening pattern aligned with said electroform cavity pattern; and   electrodepositing a die material into said electroform cavity pattern through said opening pattern in said shield to fill said electroform cavity pattern.   
     
     
       11. The method defined by claim 10 wherein said shield is composed of a thin sheet of acetate and an adhesive film. 
     
     
       12. A method of making replicas of a master stamping die having a master die pattern in relief, comprising: making a negative mold of said master stamping die having a negative mold cavity pattern corresponding to said master die pattern;   electrodepositing a layer of nickel die-forming material on said negative mold to create a replica die electroform having a cavity pattern like said mold cavity pattern;   electrodepositing on said electroform a 0.003" to 0.007" thick preparatory shield adherence layer of copper;   using the master stamping die as a cutting die, cutting from a thin sheet of acetate a shield having an opening pattern having generally the outline of said electroform cavity pattern;   laminating said shield on said replica die electroform with said opening pattern aligned with said electroform cavity pattern;   electrodepositing copper into said cavity pattern through said opening pattern in said shield to fill said electroform cavity pattern; and   milling or grinding away any excess copper fill.   
     
     
       13. An in-process article of manufacture developed during the replication of a master stamping die having a master die pattern, comprising: a negative mold of the master stamping die having a cavity pattern corresponding to said master die pattern;   a replica die electroform comprising an electrodeposit of one or more layers of die forming material on said negative mold;   an electrically insulative shield having an opening pattern generally outlining said cavity pattern of said negative mold as replicated in said electroform, said shield being laminated on said electroform with said opening pattern aligned with said cavity pattern in said electroform; and   an electrodeposit of die material in said cavity pattern in said electroform.   
     
     
       14. The article defined by claim 13 wherein said electrically insulative shield comprising a thin sheet of plastic material and an adhesive film. 
     
     
       15. The article defined by claim 14 wherein said shield is composed of acetate. 
     
     
       16. The article defined by claim 14 wherein said electroform is composed of a primary layer of nickel followed by a thin plating of copper to promote adherence of said shield. 
     
     
       17. The article defined by claim 13 wherein said electrodeposit of material into said cavity pattern in said electroform is composed of copper.